Paramagnetic resonance absorption in single crystals of the copper Tutton salts has been investigated at 3.10 cm wavelength between 90° k and room temperature. In salts diluted with zinc Tutton salt the hyperfine lines are clearly resolved at 90° k but broaden and merge into one another as the temperature is raised. From these measurements the spin-lattice relaxation time τ can be estimated and is found to be about 2×10^-9 sec It is found that 1/τ varies linearly with temperature between 150° k and 290° k An investigation of the crystalline field in the Tutton salts shows that for the concentrated salts the field has a strong rhombic component above 150° k, whilst in the salts diluted with zinc to less than 1% copper the crystalline field has tetragonal symmetry at 290° k, but the tetragonal axis lies in a plane perpendicular to that containing the tetragonal axis at 90° k.